1 files changed, 465 insertions, 0 deletions
diff --git a/builtin/diff.c b/builtin/diff.c
new file mode 100644
index 000000000000..42ac803091e6
--- /dev/null
+++ b/builtin/diff.c
@@ -0,0 +1,465 @@
+/*
+ * Builtin "git diff"
+ *
+ * Copyright (c) 2006 Junio C Hamano
+ */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#include "cache.h"
+#include "config.h"
+#include "lockfile.h"
+#include "color.h"
+#include "commit.h"
+#include "blob.h"
+#include "tag.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "log-tree.h"
+#include "builtin.h"
+#include "submodule.h"
+#include "sha1-array.h"
+
+#define DIFF_NO_INDEX_EXPLICIT 1
+#define DIFF_NO_INDEX_IMPLICIT 2
+
+static const char builtin_diff_usage[] =
+"git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
+
+static const char *blob_path(struct object_array_entry *entry)
+{
+	return entry->path ? entry->path : entry->name;
+}
+
+static void stuff_change(struct diff_options *opt,
+			 unsigned old_mode, unsigned new_mode,
+			 const struct object_id *old_oid,
+			 const struct object_id *new_oid,
+			 int old_oid_valid,
+			 int new_oid_valid,
+			 const char *old_path,
+			 const char *new_path)
+{
+	struct diff_filespec *one, *two;
+
+	if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
+	    oideq(old_oid, new_oid) && (old_mode == new_mode))
+		return;
+
+	if (opt->flags.reverse_diff) {
+		SWAP(old_mode, new_mode);
+		SWAP(old_oid, new_oid);
+		SWAP(old_path, new_path);
+	}
+
+	if (opt->prefix &&
+	    (strncmp(old_path, opt->prefix, opt->prefix_length) ||
+	     strncmp(new_path, opt->prefix, opt->prefix_length)))
+		return;
+
+	one = alloc_filespec(old_path);
+	two = alloc_filespec(new_path);
+	fill_filespec(one, old_oid, old_oid_valid, old_mode);
+	fill_filespec(two, new_oid, new_oid_valid, new_mode);
+
+	diff_queue(&diff_queued_diff, one, two);
+}
+
+static int builtin_diff_b_f(struct rev_info *revs,
+			    int argc, const char **argv,
+			    struct object_array_entry **blob)
+{
+	/* Blob vs file in the working tree*/
+	struct stat st;
+	const char *path;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
+	path = revs->prune_data.items[0].match;
+
+	if (lstat(path, &st))
+		die_errno(_("failed to stat '%s'"), path);
+	if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
+		die(_("'%s': not a regular file or symlink"), path);
+
+	diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
+
+	if (blob[0]->mode == S_IFINVALID)
+		blob[0]->mode = canon_mode(st.st_mode);
+
+	stuff_change(&revs->diffopt,
+		     blob[0]->mode, canon_mode(st.st_mode),
+		     &blob[0]->item->oid, &null_oid,
+		     1, 0,
+		     blob[0]->path ? blob[0]->path : path,
+		     path);
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_blobs(struct rev_info *revs,
+			      int argc, const char **argv,
+			      struct object_array_entry **blob)
+{
+	const unsigned mode = canon_mode(S_IFREG | 0644);
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (blob[0]->mode == S_IFINVALID)
+		blob[0]->mode = mode;
+
+	if (blob[1]->mode == S_IFINVALID)
+		blob[1]->mode = mode;
+
+	stuff_change(&revs->diffopt,
+		     blob[0]->mode, blob[1]->mode,
+		     &blob[0]->item->oid, &blob[1]->item->oid,
+		     1, 1,
+		     blob_path(blob[0]), blob_path(blob[1]));
+	diffcore_std(&revs->diffopt);
+	diff_flush(&revs->diffopt);
+	return 0;
+}
+
+static int builtin_diff_index(struct rev_info *revs,
+			      int argc, const char **argv)
+{
+	int cached = 0;
+	while (1 < argc) {
+		const char *arg = argv[1];
+		if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
+			cached = 1;
+		else
+			usage(builtin_diff_usage);
+		argv++; argc--;
+	}
+	/*
+	 * Make sure there is one revision (i.e. pending object),
+	 * and there is no revision filtering parameters.
+	 */
+	if (revs->pending.nr != 1 ||
+	    revs->max_count != -1 || revs->min_age != -1 ||
+	    revs->max_age != -1)
+		usage(builtin_diff_usage);
+	if (!cached) {
+		setup_work_tree();
+		if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
+			perror("read_cache_preload");
+			return -1;
+		}
+	} else if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
+	return run_diff_index(revs, cached);
+}
+
+static int builtin_diff_tree(struct rev_info *revs,
+			     int argc, const char **argv,
+			     struct object_array_entry *ent0,
+			     struct object_array_entry *ent1)
+{
+	const struct object_id *(oid[2]);
+	int swap = 0;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	/*
+	 * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
+	 * swap them.
+	 */
+	if (ent1->item->flags & UNINTERESTING)
+		swap = 1;
+	oid[swap] = &ent0->item->oid;
+	oid[1 - swap] = &ent1->item->oid;
+	diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
+	log_tree_diff_flush(revs);
+	return 0;
+}
+
+static int builtin_diff_combined(struct rev_info *revs,
+				 int argc, const char **argv,
+				 struct object_array_entry *ent,
+				 int ents)
+{
+	struct oid_array parents = OID_ARRAY_INIT;
+	int i;
+
+	if (argc > 1)
+		usage(builtin_diff_usage);
+
+	if (!revs->dense_combined_merges && !revs->combine_merges)
+		revs->dense_combined_merges = revs->combine_merges = 1;
+	for (i = 1; i < ents; i++)
+		oid_array_append(&parents, &ent[i].item->oid);
+	diff_tree_combined(&ent[0].item->oid, &parents,
+			   revs->dense_combined_merges, revs);
+	oid_array_clear(&parents);
+	return 0;
+}
+
+static void refresh_index_quietly(void)
+{
+	struct lock_file lock_file = LOCK_INIT;
+	int fd;
+
+	fd = hold_locked_index(&lock_file, 0);
+	if (fd < 0)
+		return;
+	discard_cache();
+	read_cache();
+	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
+	repo_update_index_if_able(the_repository, &lock_file);
+}
+
+static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
+{
+	unsigned int options = 0;
+
+	while (1 < argc && argv[1][0] == '-') {
+		if (!strcmp(argv[1], "--base"))
+			revs->max_count = 1;
+		else if (!strcmp(argv[1], "--ours"))
+			revs->max_count = 2;
+		else if (!strcmp(argv[1], "--theirs"))
+			revs->max_count = 3;
+		else if (!strcmp(argv[1], "-q"))
+			options |= DIFF_SILENT_ON_REMOVED;
+		else if (!strcmp(argv[1], "-h"))
+			usage(builtin_diff_usage);
+		else
+			return error(_("invalid option: %s"), argv[1]);
+		argv++; argc--;
+	}
+
+	/*
+	 * "diff --base" should not combine merges because it was not
+	 * asked to.  "diff -c" should not densify (if the user wants
+	 * dense one, --cc can be explicitly asked for, or just rely
+	 * on the default).
+	 */
+	if (revs->max_count == -1 && !revs->combine_merges &&
+	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
+		revs->combine_merges = revs->dense_combined_merges = 1;
+
+	setup_work_tree();
+	if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
+		perror("read_cache_preload");
+		return -1;
+	}
+	return run_diff_files(revs, options);
+}
+
+int cmd_diff(int argc, const char **argv, const char *prefix)
+{
+	int i;
+	struct rev_info rev;
+	struct object_array ent = OBJECT_ARRAY_INIT;
+	int blobs = 0, paths = 0;
+	struct object_array_entry *blob[2];
+	int nongit = 0, no_index = 0;
+	int result = 0;
+
+	/*
+	 * We could get N tree-ish in the rev.pending_objects list.
+	 * Also there could be M blobs there, and P pathspecs.
+	 *
+	 * N=0, M=0:
+	 *	cache vs files (diff-files)
+	 * N=0, M=2:
+	 *      compare two random blobs.  P must be zero.
+	 * N=0, M=1, P=1:
+	 *	compare a blob with a working tree file.
+	 *
+	 * N=1, M=0:
+	 *      tree vs cache (diff-index --cached)
+	 *
+	 * N=2, M=0:
+	 *      tree vs tree (diff-tree)
+	 *
+	 * N=0, M=0, P=2:
+	 *      compare two filesystem entities (aka --no-index).
+	 *
+	 * Other cases are errors.
+	 */
+
+	/* Were we asked to do --no-index explicitly? */
+	for (i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "--")) {
+			i++;
+			break;
+		}
+		if (!strcmp(argv[i], "--no-index"))
+			no_index = DIFF_NO_INDEX_EXPLICIT;
+		if (argv[i][0] != '-')
+			break;
+	}
+
+	prefix = setup_git_directory_gently(&nongit);
+
+	if (!no_index) {
+		/*
+		 * Treat git diff with at least one path outside of the
+		 * repo the same as if the command would have been executed
+		 * outside of a git repository.  In this case it behaves
+		 * the same way as "git diff --no-index <a> <b>", which acts
+		 * as a colourful "diff" replacement.
+		 */
+		if (nongit || ((argc == i + 2) &&
+			       (!path_inside_repo(prefix, argv[i]) ||
+				!path_inside_repo(prefix, argv[i + 1]))))
+			no_index = DIFF_NO_INDEX_IMPLICIT;
+	}
+
+	init_diff_ui_defaults();
+	git_config(git_diff_ui_config, NULL);
+	precompose_argv(argc, argv);
+
+	repo_init_revisions(the_repository, &rev, prefix);
+
+	/* Set up defaults that will apply to both no-index and regular diffs. */
+	rev.diffopt.stat_width = -1;
+	rev.diffopt.stat_graph_width = -1;
+	rev.diffopt.flags.allow_external = 1;
+	rev.diffopt.flags.allow_textconv = 1;
+
+	/* If this is a no-index diff, just run it and exit there. */
+	if (no_index)
+		exit(diff_no_index(&rev, no_index == DIFF_NO_INDEX_IMPLICIT,
+				   argc, argv));
+
+
+	/*
+	 * Otherwise, we are doing the usual "git" diff; set up any
+	 * further defaults that apply to regular diffs.
+	 */
+	rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
+
+	/*
+	 * Default to intent-to-add entries invisible in the
+	 * index. This makes them show up as new files in diff-files
+	 * and not at all in diff-cached.
+	 */
+	rev.diffopt.ita_invisible_in_index = 1;
+
+	if (nongit)
+		die(_("Not a git repository"));
+	argc = setup_revisions(argc, argv, &rev, NULL);
+	if (!rev.diffopt.output_format) {
+		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+		diff_setup_done(&rev.diffopt);
+	}
+
+	rev.diffopt.flags.recursive = 1;
+
+	setup_diff_pager(&rev.diffopt);
+
+	/*
+	 * Do we have --cached and not have a pending object, then
+	 * default to HEAD by hand.  Eek.
+	 */
+	if (!rev.pending.nr) {
+		int i;
+		for (i = 1; i < argc; i++) {
+			const char *arg = argv[i];
+			if (!strcmp(arg, "--"))
+				break;
+			else if (!strcmp(arg, "--cached") ||
+				 !strcmp(arg, "--staged")) {
+				add_head_to_pending(&rev);
+				if (!rev.pending.nr) {
+					struct tree *tree;
+					tree = lookup_tree(the_repository,
+							   the_repository->hash_algo->empty_tree);
+					add_pending_object(&rev, &tree->object, "HEAD");
+				}
+				break;
+			}
+		}
+	}
+
+	for (i = 0; i < rev.pending.nr; i++) {
+		struct object_array_entry *entry = &rev.pending.objects[i];
+		struct object *obj = entry->item;
+		const char *name = entry->name;
+		int flags = (obj->flags & UNINTERESTING);
+		if (!obj->parsed)
+			obj = parse_object(the_repository, &obj->oid);
+		obj = deref_tag(the_repository, obj, NULL, 0);
+		if (!obj)
+			die(_("invalid object '%s' given."), name);
+		if (obj->type == OBJ_COMMIT)
+			obj = &get_commit_tree(((struct commit *)obj))->object;
+
+		if (obj->type == OBJ_TREE) {
+			obj->flags |= flags;
+			add_object_array(obj, name, &ent);
+		} else if (obj->type == OBJ_BLOB) {
+			if (2 <= blobs)
+				die(_("more than two blobs given: '%s'"), name);
+			blob[blobs] = entry;
+			blobs++;
+
+		} else {
+			die(_("unhandled object '%s' given."), name);
+		}
+	}
+	if (rev.prune_data.nr)
+		paths += rev.prune_data.nr;
+
+	/*
+	 * Now, do the arguments look reasonable?
+	 */
+	if (!ent.nr) {
+		switch (blobs) {
+		case 0:
+			result = builtin_diff_files(&rev, argc, argv);
+			break;
+		case 1:
+			if (paths != 1)
+				usage(builtin_diff_usage);
+			result = builtin_diff_b_f(&rev, argc, argv, blob);
+			break;
+		case 2:
+			if (paths)
+				usage(builtin_diff_usage);
+			result = builtin_diff_blobs(&rev, argc, argv, blob);
+			break;
+		default:
+			usage(builtin_diff_usage);
+		}
+	}
+	else if (blobs)
+		usage(builtin_diff_usage);
+	else if (ent.nr == 1)
+		result = builtin_diff_index(&rev, argc, argv);
+	else if (ent.nr == 2)
+		result = builtin_diff_tree(&rev, argc, argv,
+					   &ent.objects[0], &ent.objects[1]);
+	else if (ent.objects[0].item->flags & UNINTERESTING) {
+		/*
+		 * diff A...B where there is at least one merge base
+		 * between A and B.  We have ent.objects[0] ==
+		 * merge-base, ent.objects[ents-2] == A, and
+		 * ent.objects[ents-1] == B.  Show diff between the
+		 * base and B.  Note that we pick one merge base at
+		 * random if there are more than one.
+		 */
+		result = builtin_diff_tree(&rev, argc, argv,
+					   &ent.objects[0],
+					   &ent.objects[ent.nr-1]);
+	} else
+		result = builtin_diff_combined(&rev, argc, argv,
+					       ent.objects, ent.nr);
+	result = diff_result_code(&rev.diffopt, result);
+	if (1 < rev.diffopt.skip_stat_unmatch)
+		refresh_index_quietly();
+	UNLEAK(rev);
+	UNLEAK(ent);
+	UNLEAK(blob);
+	return result;
+}